Semiconductor devices are used in a variety of electronic applications, such as personal computers, cell phones, digital cameras, and other electronic equipment. The semiconductor industry continues to improve the integration density of various electronic components (e.g., transistors, diodes, resistors, capacitors, etc.) by continual reductions in minimum feature size, which allows more components to be integrated into a given area. These smaller electronic components also require smaller packages that utilize less area than the packages of the past, in some applications.
During the manufacturing of the semiconductor devices, various processing steps are used to fabricate integrated circuits on a semiconductor wafer. For example, the processes include an electroplating process for deposition of conductive layers over the semiconductor wafer, thereby forming the integrated circuits. Generally, an electroplating process includes depositing or plating out positively charged ions (such as metal ions) onto a negatively charged substrate (such as the semiconductor wafer), which is used as a source of electrons. As a result, a seed layer (or a metal layer) is first deposited over the semiconductor wafer to provide an electrical path across the surfaces. An electrical current is then supplied to the seed layer, thereby electroplating the semiconductor wafer surface with an appropriate metal (such as copper, aluminum or another suitable material).
An electroplating device or system is used to perform the electroplating process. For example, the electroplating device includes an electrolyte tank, a container or in the electrolyte tank and an anode in the container. The negatively charged substrate to be electroplated is in contact with a plating solution in the container so as to deposit a conductive layer thereon. However, variations in the plating solution may reduce the quality of the electroplating. Therefore, the plating solution needs to be kept clean and have a chemical composition within specific limits.
Although numerous improvements to the electroplating process have been invented, they have not been entirely satisfactory in all respects. Consequently, it would be desirable to provide solutions to improve the quality of the electroplating process, thereby enhancing the electrical performance and reliability of the semiconductor devices.